NY · GEOID 36059

Nassau County area

Nassau County, New York covers 453.4 square miles: 284.5 square miles of land and 168.8 square miles of water.

Official Census measurements2026 Gazetteer · retrieved September 27, 2026
Land area284.5 mi²
Water area168.8 mi²
Total area453.4 mi²
National land rank#2833

County outline

Generalized outline of Nassau County, New York
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Nassau County is located

Nassau County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 62.8% of Nassau County’s measured area and water for 37.2%. Its combined area converts to 1,174.3 square kilometers or approximately 290,164 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land284.544736.966182,108.2
Water168.837437.286108,055.7
Total453.3811,174.251290,163.8

How Nassau County compares

By original Census land area, Nassau County ranks #54 of 62 in New York and #2833 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.435 times the New York county-equivalent median of 653.7 square miles. It accounts for 0.6% of the combined county land area in the state.

See the complete New York ranking · What counts as a county equivalent?

What stands out about Nassau County?

Nassau County has more land than 389 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Nassau County284.5 mi²
New York median653.7 mi²
National median604.5 mi²

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Nassau County at #2,331 nationally by total area, 502 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 37.2%, compared with a national county-equivalent median of 1.2% — 36.1 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Nassau County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#2832Turner County, Georgia285.4Compare
#2833Nassau County, New York284.5This county
#2834Franklin County, Texas284.4Compare

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.

Representative coordinates

The Census internal point is 40.729504, -73.589403. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.

Source and precision

U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 736,965,427 m²; AWATER: 437,285,877 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How many acres of land are in Nassau County?

The land measurement converts to approximately 182,108 acres. Including water, total area is approximately 290,164 acres. One square mile equals 640 acres.

Why might another source show a different area?

Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.

Can this establish a property boundary?

No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.

Cite this county

Download the complete CSV or JSON dataset